Recently, to prevent health hazard attributed to foods containing allergic substances, requests for information service by indication thereof have increased. The indication of foods containing allergic substances has been made obligatory with enforcement of amendments to the Statutes on the Food Sanitation Law in April, 2001. In particular, with respect to five items (specified raw materials) of eggs, milk, and wheat which cause allergy most often, and buckwheat and peanuts which cause serious symptoms, it has been made obligatory to perform proper indication over the entire distribution stage.
There are individual differences as to what food people recognize as an allergen as the allergic substance. Thus, if a specified substance contained in the food is properly indicated even when the specified substance is contained in a trace amount, a person who ingests the food can know the presence/absence of the allergen contained in the food, so that health hazard can be prevented. However, it has been difficult to detect the presence/absence of a trace amount of a specified substance in a food having been heated or otherwise processed, by conventionally known methods for food analysis.
In addition, when a specified raw material is used by a producer in his or her company, it is a matter of course that the specified raw material can be indicated on processed foods. However, when a specified raw material is used as an intermediate material of a final product, it is hard in some cases to confirm the presence/absence of the specified raw material contained in a trace amount, particularly in a purchased intermediate material. Unintended inclusion may also actually occur.
Therefore, for food manufacturers, it is important to precisely comprehend food additives such as processing aids and carry-over remaining in trace amounts or actual states of mutual contamination between manufacturing lines, and take proper measures as well as provide consumers with correct information based on the laws. Therefore, it has been desired to provide a technology of precisely analyzing allergic substances.
In particular, wheat is very often used as a raw material of various food products, and in most cases, the use of wheat in final products cannot be determined only from the appearance of the food product. Moreover, allergic symptoms due to wheat are serious, the number of patients is prone to increase along with the diet westernization, and wheat is now one of the major substances causative of immediate allergy.
Thus, wheat is defined as one of the specified raw materials in the indication of foods containing allergic substances under the Food Sanitation Law, and it has been made obligatory to indicate the presence of wheat when the wheat is included in the food.
However, there has been also no proper measuring method to detect the wheat, and a reliable measuring method for a trace amount component has been desired.
An object of the invention is development of a method for measuring the presence/absence of wheat in a food based on the findings obtained from attempts to construct primers specific to wheat, to identify the detection limit by an analysis system thereof, and to apply the primers to processed foods for the purpose of developing a method for precisely analyzing the presence/absence of the wheat included in the food.